W.P.T.M. Mali

Management of Lung Nodules Detected by Volume CT Scanning

BACKGROUNDnThe use of multidetector computed tomography (CT) in lung-cancer screening trials involving subjects with an increased risk of lung cancer has highlighted the problem for the clinician of deciding on the best course of action when noncalcified pulmonary nodules are detected by CT.nnnMETHODSnA total of 7557 participants underwent CT screening in years 1, 2, and 4 of a randomized trial of lung-cancer screening. We used software to evaluate a noncalcified nodule according to its volume or volume-doubling time. Growth was defined as an increase in volume of at least 25% between two scans. The first-round screening test was considered to be negative if the volume of a nodule was less than 50 mm(3), if it was 50 to 500 mm(3) but had not grown by the time of the 3-month follow-up CT, or if, in the case of those that had grown, the volume-doubling time was 400 days or more.nnnRESULTSnIn the first and second rounds of screening, 2.6% and 1.8% of the participants, respectively, had a positive test result. In round one, the sensitivity of the screen was 94.6% (95% confidence interval [CI], 86.5 to 98.0) and the negative predictive value 99.9% (95% CI, 99.9 to 100.0). In the 7361 subjects with a negative screening result in round one, 20 lung cancers were detected after 2 years of follow-up.nnnCONCLUSIONSnAmong subjects at high risk for lung cancer who were screened in three rounds of CT scanning and in whom noncalcified pulmonary nodules were evaluated according to volume and volume-doubling time, the chances of finding lung cancer 1 and 2 years after a negative first-round test were 1 in 1000 and 3 in 1000, respectively. (Current Controlled Trials number, ISRCTN63545820.)

Diffusion-Weighted Magnetic Resonance Imaging in Acute Stroke

BACKGROUND AND PURPOSEnDiffusion-weighted MRI (DWI) is highly sensitive in detecting early cerebral ischemic changes in acute stroke patients. In this study we compared the sensitivity of DWI with that of conventional MRI techniques. Furthermore, we investigated the prognostic value of the volume of ischemic lesions on DWI scans and of the apparent diffusion coefficient (ADC).nnnMETHODSnWe performed DWI, fluid-attenuated inversion recovery, spin-echo T2-weighted MRI, and spin-echo proton density-weighted MRI in 42 patients with acute stroke and 15 control subjects. The volume of ischemic lesions was measured on early (<60 hours after onset) and follow-up MRI scans. Clinical outcome was measured 4 months after onset of symptoms with the National Institutes of Health Stroke Scale, the Barthel Index, and the Rankin Scale.nnnRESULTSnWith DWI, 98% of the ischemic lesions were detected, and with fluid-attenuated inversion recovery, 91% were detected, whereas with early T2-weighted or proton density-weighted scans, only 71% (P=0.002, chi2) and 80% (P=0.02, chi2) of lesions, respectively, were found. Lesion volume on early DWI scans correlated significantly with clinical outcome ratings (P<0.01). In patients with a first-ever stroke, a lesion volume of < or =22 mL on DWI predicted good outcome with a 75% sensitivity and a 100% specificity. The mean ADC of ischemic lesions was 29% lower than the ADC of normal-appearing parts of the brain (P<0.001). The ADC ratio correlated significantly with clinical outcome (P<0.05).nnnCONCLUSIONSnDWI is a better imaging method than conventional MRI in detecting early ischemic lesions in stroke patients. Lesion size as measured on DWI scans and, to a lesser extent, ADC values are potential parameters for predicting clinical outcome in acute stroke patients.

Diagnostic accuracy of large-core needle biopsy for nonpalpable breast disease : a meta-analysis

For the evaluation of non-palpable lesions of the breast, image-guided large-core needle biopsies are increasingly replacing needle-localized open breast biopsies. In this study, the diagnostic accuracy of this minimally invasive technique was evaluated by reviewing the available literature. Five cohort studies were included in a meta-analysis. Sensitivity rate, histological agreement between needle biopsy and subsequent surgery or long-term mammographic follow-up and clinical consequences for different disease prevalences were assessed. The sensitivity rate of large-core needle biopsy for the diagnosis of breast cancer was high (97%). The reclassified agreement rate between core biopsy and subsequent surgical biopsy or long-term mammographic follow-up was also high (94%). In case of 20% breast cancer prevalence among women referred after screening (as in the US), the risk of breast cancer despite benign large-core needle biopsy result is less than 1%. In European countries, however, prevalence of breast cancer among referred women is 60–70%. This would result in a risk of breast cancer despite benign large-core needle biopsy result of 4–6%. The results of this meta-analysis indicate that the image guided large-core needle biopsy is a promising alternative for the needle localized breast biopsy. However, additional research is needed to explore the limiting factors of the technique. Without such detailed knowledge, a benign histological diagnosis on large-core needle biopsy in countries with high prevalence of malignancy among referred women should be interpreted with caution.

CT-angiography of abdominal aortic aneurysms after transfemoral endovascular aneurysm management

OBJECTIVEnTo evaluate short-term effect of Transfemoral Endovascular Aneurysm Management (TEAM) on aortic diameters and volumes after aneurysm exclusion, using CT-angiography.nnnDESIGNnAnalysis of preoperative, 1 week postoperative and 6 months postoperative CT measurements.nnnSETTINGnUniversity Hospital.nnnMATERIALSnNine patients treated with an endovascular tube prosthesis.nnnCHIEF OUTCOME MEASURESnTrue cross-sectional diameters of the aorta and the aneurysm, volume of the infrarenal aortic lumen, of the thrombus and of the iliac arteries and length of the aorta and of the endovascular prosthesis.nnnMAIN RESULTSnCT-angiography detected shrinkage of the aneurysm in seven patients. Aneurysm growth was observed in one patient with persistent flow outside the graft and in one patient with fully thrombosed aneurysm sac. In the two patients with increasing thrombus volume, the volume of the aortic lumen decreased.nnnCONCLUSIONSnAlthough successful aneurysm exclusion can be confirmed by maximum aneurysm diameter measurement, changes in aortic lumen volume and thrombus volume may be more appropriate to discriminate successful from failed exclusion.

MRA Flow Quantification in Patients With a Symptomatic Internal Carotid Artery Occlusion

BACKGROUND AND PURPOSEnFlow measurements in the collateral arteries of patients with internal carotid artery (ICA) occlusions may be important to estimate the risk of future stroke. Quantitative flow measurements in cerebropetal vessels can be reliably assessed by means of magnetic resonance angiography (MRA).nnnMETHODSnFifty-four patients with transient or minor ischemic neurological deficits and an angiographically proven ICA occlusion and 16 control subjects underwent two-dimensional phase-contrast MRA quantitative flow measurements through the common carotid arteries, basilar artery, ICAs, and middle cerebral arteries (MCA).nnnRESULTSnPatients with a unilateral ICA occlusion and a 0% to 69% stenosis of the contralateral ICA had increased flow in the contralateral ICA (P < .005) and in the basilar artery (P < .005) compared with control subjects. Even patients with a 70% to 99% stenosis contralateral to the ICA occlusion had increased flow in the ICA (P < .05) as well as increased flow in the basilar artery (P < .001). Total cerebropetal flow was not significantly different between these patients and control subjects. Patients with bilateral ICA occlusions had an increased flow in the basilar artery (P < .001), while the total cerebropetal flow was less than in control subjects (P < .001). In all patients, flow was decreased in the ipsilateral MCA (P < .001) and in the contralateral MCA (P < .05).nnnCONCLUSIONSnThe contralateral ICA is the main supplying artery in patients with an ICA occlusion. Total cerebropetal flow decreases only when both ICAs are occluded. In patients with symptomatic ICA occlusions, an open contralateral ICA is probably important to retain the cerebral blood flow within normal limits.

Cerebral Metabolism of Patients With Stenosis or Occlusion of the Internal Carotid Artery A 1H-MR Spectroscopic Imaging Study

BACKGROUND AND PURPOSEnOcclusion or severe stenosis of extracranial vessels may lead to hypoperfusion without overt infarction of brain tissue. The aim of this study was to investigate whether occlusion of the internal carotid artery or stenosis with reduction in diameter of more than 70% leads to altered cerebral metabolism in regions in which no infarcts are visible with magnetic resonance imaging.nnnMETHODSnWe studied 10 control subjects and 55 patients with transient or nondisabling cerebral ischemia (25 patients with severe unilateral stenosis, 15 patients with unilateral occlusion, and 15 patients with bilateral severe stenosis or occlusion of the internal carotid artery). All subjects underwent magnetic resonance imaging and 1H magnetic resonance spectroscopic imaging. Cerebral metabolism was studied by assessing ratios of N-acetyl aspartate (NAA) to choline and to creatine as well as lactate from noninfarcted frontal, mesial, and parietal regions in the centrum semiovale in both hemispheres.nnnRESULTSnAll patients with unilateral stenosis or occlusion of the internal carotid artery had decreased NAA/choline ratios in noninfarcted areas in the hemisphere on the side of the stenosis or occlusion and normal NAA/choline ratios in the contralateral hemisphere. Patients with bilateral stenosis or occlusion had decreased NAA/choline ratios in both hemispheres. In one third of all patients, cerebral lactate was found in regions without abnormalities on magnetic resonance imaging.nnnCONCLUSIONSnA severe reduction in the diameter of the internal carotid artery affects cerebral metabolism in regions that are not infarcted. These changes are reflected in a decreased NAA/choline ratio and a high incidence of cerebral lactate. These regions are probably at risk for infarction in the long term or if cerebral perfusion decreases further.

Cognition after carotid endarterectomy or stenting A randomized comparison

Objective: To compare the effect on cognition of carotid artery stenting (CAS) and carotid endarterectomy (CEA) for symptomatic carotid artery stenosis. Methods: Patients randomized to CAS or CEA in the International Carotid Stenting Study (ICSS; ISRCTN25337470) at 2 participating centers underwent detailed neuropsychological examinations (NPE) before and 6 months after revascularization. Ischemic brain lesions were assessed with diffusion-weighted imaging before and within 3 days after revascularization. Cognitive test results were standardized into z scores, from which a cognitive sumscore was calculated. The primary outcome was the change in cognitive sumscore between baseline and follow-up. Results: Of the 1,713 patients included in ICSS, 177 were enrolled in the 2 centers during the substudy period, of whom 140 had an NPE at baseline and 120 at follow-up. One patient with an unreliable baseline NPE was excluded. CAS was associated with a larger decrease in cognition than CEA, but the between-group difference was not statistically significant: −0.17 (95% CI −0.38 to 0.03; p = 0.092). Eighty-nine patients had a pretreatment MRI and 64 within 3 days after revascularization. New ischemic lesions were found twice as often after CAS than after CEA (relative risk 2.1; 95% CI 1.0 to 4.4; p = 0.041). Conclusions: Differences between CAS and CEA in effect on cognition were not statistically significant, despite a substantially higher rate of new ischemic lesions after CAS than after CEA. Classification of Evidence: This study provides Class III evidence that any difference between the effects of CAS and CEA on cognition at 6 months after revascularization is small.

Efficacy of ‘radioguided occult lesion localisation’ (ROLL) versus ‘wire-guided localisation’ (WGL) in breast conserving surgery for non-palpable breast cancer: a randomised controlled multicentre trial

For the management of non-palpable breast cancer, accurate pre-operative localisation is essential to achieve complete resection with optimal cosmetic results. Radioguided occult lesions localisation (ROLL) uses the radiotracer, injected intra-tumourally for sentinel lymph node identification to guide surgical excision of the primary tumour. In a multicentre randomised controlled trial, we determined if ROLL is superior to the standard of care (i.e. wire-guided localisation, WGL) for preoperative tumour localisation. Women (>18 years.) with histologically proven non-palpable breast cancer and eligible for breast conserving treatment with sentinel node procedure were randomised to ROLL or WGL. Patients allocated to ROLL received an intra-tumoural dose of 120 Mbq technetium-99xa0m nanocolloid. The tumour was surgically removed, guided by gamma probe detection. In the WGL group, ultrasound- or mammography-guided insertion of a hooked wire provided surgical guidance for excision of the primary tumour. Primary outcome measures were the proportion of complete tumour excisions (i.e. with negative margins), the proportion of patients requiring re-excision and the volume of tissue removed. Data were analysed according to intention-to-treat principle. This study is registered at ClinincalTrials.gov, number NCT00539474. In total, 314 patients with 316 invasive breast cancers were enrolled. Complete tumour removal with negative margins was achieved in 140/162 (86xa0%) patients in the ROLL group versus 134/152 (88xa0%) patients in the WGL group (Pxa0=xa00.644). Re-excision was required in 19/162 (12xa0%) patients in the ROLL group versus 15/152 (10xa0%) (Pxa0=xa00.587) in the WGL group. Specimen volumes in the ROLL arm were significantly larger than those in the WGL arm (71 vs. 64xa0cm3, Pxa0=xa00.017). No significant differences were seen in the duration and difficulty of the radiological and surgical procedures, the success rate of the sentinel node procedure, and cosmetic outcomes. In this first multicentre randomised controlled comparison of ROLL versus WGL in patients with histologically proven breast cancer, ROLL is comparable to WGL in terms of complete tumour excision and re-excision rates. ROLL, however, leads to excision of larger tissue volumes. Therefore, ROLL cannot replace WGL as the standard of care.

Noninvasive MR imaging of cerebral perfusion in patients with a carotid artery stenosis

Background: Arterial spin labeling (ASL) perfusion MRI with image acquisition at multiple delay times can be used to measure delays in the arrival of arterial blood to the brain. We assessed the effect of a symptomatic internal carotid artery (ICA) stenosis on ASL timing parameters, and evaluated the effect of collateral flow through the circle of Willis. Methods: Forty-four functionally independent patients (30 men, 69 ± 9 years) with a recently symptomatic ICA stenosis ≥50% and 34 sex-matched and age-matched healthy volunteers were investigated. Magnetic resonance angiography and 2-dimensional phase-contrast imaging were used to assess collateral flow in the circle of Willis. Results: In the hemisphere ipsilateral to the ICA stenosis, cerebral blood flow (CBF) was lower (p < 0.01) in the anterior frontal, posterior frontal, parieto-occipital, and occipital regions than in control subjects. The transit times were prolonged (p < 0.01) in the ipsilateral anterior frontal, posterior frontal, and frontoparietal regions when compared with the control subjects. The trailing edge time was prolonged (p < 0.01) in the ipsilateral frontoparietal region when compared to the control subjects. In the 27 patients without a contralateral stenosis, the trailing edge was longer (p < 0.01) in the ipsilateral posterior frontal, frontoparietal, and parieto-occipital regions than in the contralateral regions. Collateral flow via the circle of Willis did not affect CBF and transit or trailing edge times. Conclusion: Arterial spin labeling MRI is a noninvasive tool for imaging cerebral blood flow and delays in the arrival of arterial blood to the brain, and can potentially provide valuable information on the quality of perfusion to the brain in patients with cerebrovascular disease.

Automated and Visual Scoring Methods of Cerebral White Matter Hyperintensities: Relation with Age and Cognitive Function

Background and Purpose: A reliable scoring method for ischemic cerebral white matter hyperintensities (WMH) will help to clarify the causes and consequences of these brain lesions. We compared an automated and two visual WMH scoring methods in their relations with age and cognitive function. Methods: MRI of the brain was performed on 154 participants of the Utrecht Diabetic Encephalopathy Study. WMH volumes were obtained with an automated segmentation method. Visual rating of deep and periventricular WMH (DWMH and PWMH) was performed with the Scheltens scale and the Rotterdam Scan Study (RSS) scale, respectively. Cognition was assessed with a battery of 11 tests. Results: Within the whole study group, the association with age was most evident for the automated measured WMH volume (β = 0.43, 95% CI = 0.29–0.57). With regard to cognition, automated measured WMH volume and Scheltens DWMH were significantly associated with information processing speed (β = –0.22, 95% CI = –0.40 to –0.06; β = –0.26, 95% CI = –0.42 to –0.10), whereas RSS PWMH were associated with attention and executive function (β = –0.19, 95% CI = –0.36 to –0.02). Conclusion: Measurements of WMH with an automated quantitative segmentation method are comparable with visual rating scales and highly suitable for use in future studies to assess the relationship between WMH and subtle impairments in cognitive function.